Re: [PATCH 1/2] tty: serial: msm_serial: Fix lockup for sysrq and oops

From: Leo Yan
Date: Sun Nov 24 2019 - 20:21:33 EST


Hi Jeffrey,

On Sun, Nov 24, 2019 at 04:00:21PM -0700, Jeffrey Hugo wrote:
> On Sun, Nov 24, 2019 at 8:44 AM Leo Yan <leo.yan@xxxxxxxxxx> wrote:
> >
> > As the commit 677fe555cbfb ("serial: imx: Fix recursive locking bug")
> > has mentioned the uart driver might cause recursive locking between
> > normal printing and the kernel debugging facilities (e.g. sysrq and
> > oops). In the commit it gave out suggestion for fixing recursive
> > locking issue: "The solution is to avoid locking in the sysrq case
> > and trylock in the oops_in_progress case."
> >
> > This patch follows the suggestion (also used the exactly same code with
> > other serial drivers, e.g. amba-pl011.c) to fix the recursive locking
> > issue, this can avoid stuck caused by deadlock and print out log for
> > sysrq and oops.
> >
> > Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
>
> Shouldn't this patch have a Fixes tag?

Will add fixes tag in next spin.

> Was there a cover letter?

Okay, I will add cover letter for patch set v2.

Thanks for reviewing!
Leo